Safety belay fob were feeding



3, 1954 E. F. zwAcK SAFETY RELAY FOR WIRE FEEDING Filed Nov. 24, 1953 INVENTOR. Edward E Zn a CA Patented Aug. 3, 1 954 UNITED STATES PATENT OFFICE SAFETY RELAY FOR WIRE FEEDING Edward F. Zwack, New Haven, Conn. Application November 24, 1953, Serial No. 394,079

2 Claims. 1

My invention relates to improved means for feeding wire or other filamentary material into machines, and has particular utility in machines which insulate the wires used for the conduction of electricity. These machines deposit an insulating layer on the surface of the wire in a continuous operation by passing the wire through a chamber, containing rubber or other insulating compound, in a plastic consistency, and by the application of pressure, they extrude the insulating material, surrounding the wire, through the aperture of a die.

An essential element of these machines is the core-tube, through which the wire enters into the insulation chamber. This core-tube has an orifice which, in order to prevent the leakage of the compound, must conform closely to the crosssection of the uninsulated wire.

The advancing of the wire through the insulation chamber is accomplished by means of an electrically operated mechanism controlled by manual switches. The machine may include also vulcanizing, curing or cooling passages, often of considerable length, depending on the insulating material and process used.

Experience shows that these machines are subject to frequent and costly operational interruptions due to the following causes: One of the causes is that frequently enlargements occur in the wire which cannot pass through the orifice of the core-tube, as a result of which, the wire may be stopped in the core-tube and subsequently broken by the tension of the wire advancing mechanism. Another frequent cause is that, due to faulty manufacturing, the crosssection of the wire is reduced at some points so as to break under the normal tension of the wire. Another, possible cause is that, due to inattention, the spool of wire may run out before the wire-end is spliced. The usual effect of any of these causes is that the insulating compound, being under pressure, oozes out from the chamber through the aperture of the die, clogging the machine to such an extent that it can resume operation only after laborious and time consuming cleaning. As an additional damage, such tieup may also spoil a considerable amount of wire processed in the vulcanizing and curing passages of the machine.

The principal object of my invention is to pro vide a safety relay which prevents these operational interruptions of the wire insulating machines by automatically stopping the advance of the wire before the defective point has reached the machines, thereby increasing the output ca- 2 pacity of these machines and reducing the labor required for their attendance.

Another object of my invention is to provide a safety relay which is equally effective in automatically stopping the advance of the wire whether the defect consists of an enlarged crosssection or lack of continuity, thereby offering a complete protection against operational interruptions due to defective wire.

A further object of my invention is to provide a simple and inexpensive safety relay which performs the functions of two relays hitherto required to detect the enlarged cross-section and the break in the Wire, thereby reducing the first cost of the installation.

other objects and advantages of my invention will be apparent during the course of the following description.

In the accompanying drawing, wherein for the purpose of illustration, is shown a preferred embodiment of my invention,

Figure 1 is a plan view showing the arrangement of my invention in relation to the wire insulating machine.

Figure 2 is a side view of the safety relay Figure 3 is a plan view of same.

In the drawing, wherein like numerals are employed to designate like parts, in Fig. l the numeral I designates the receiving end of the wire insulating machine, carrying the core-tube 2, which is securely locked in position by a shear-pin 3. Disposed separately from the said machine is the pilot core-tube 4, identical in shape and size with the core-tube 2 and being secured to pilot holder 5 by the pilot shear-pin 6. This pilot shear-pin 6 is so designed that a tensile force of less than the breaking strength of the wire can detach the pilot core-tube 4 from the holder 5.

It is within the spirit of my invention to attach the pilot tube 4 to the holder 5 by other known means employing latches, springs, screws, pneumatic, hydraulic or magnetic means, provided the pilot core-tube can be detached from the holder by a tensile force smaller than the breaking strength of the wire.

Disposed between the machine I and the pilot core-tube 4 is the safety relay, which must be so located that the length of the wire between the machine I and the relay is greater than the stopping length of the wire. Under stopping length being meant the length of wire advance from the instant the stopping switch is actuated to the instant when the wire stops.

The safety relay, shown in detail in Figs. 2

and 3, has a base '1, adapted for being secured to a stationary support. Carried by said base is a stud 8, on which the body portion 9 is pivotally mounted, so as to permit the swinging of said body portion 9, against the pressure of the spring ID, from the normal position into the stopping position, shown by the dotted lines in Fig. 3. Secured to base I is the stop H which limits the rotation of the body portion 9 by the spring and therebydte'rmines' its normalipositioni contact arm l2, carrying the contact roller 13,

and having two positions: the normal positionin which the contact roller 1314s supportedcbythe wire 26, and the stopping position, shown by the dotted lines in Fig. 2, whichztheaarmzj21:.

20,4will:engage saidfingers .IE-and Iii and-lwill.

swing the body portion 9- into thestoppingposition, inwhichposition said fingers will permit saidpilot-core tube. tito pass by. Said fingers l5; and I6 are so.located with respect to the contact arm i2 androller l3-that when said fingers-and. the connected body portion, swing into the stopping positionsaid-roller loses the supporthotthe wire, hence, spring, will be efiectivetomove. the arm l2 into the stopping,

position.

Attached to'the contact arm I2 is an electric switch. l1, preferably of the sealed, mercury, type,

arranged for connection into the .controlcircuiti ofethe-wire advancing mechanism. by means of conductorsia and is, and so adapted that .in'the. stopping position of the arm .lzrsaidiswitch' H will effect .the stopping of..the wire advancing mechanism.

The operation of myinvention is asiollows:

, In the function of my. invention the basic idea is to simulate the behavior, which the defective" wire at presenthas in the machine, by passing the wire through a duplicate core-tube well. be-

fore it reachesth'e machine. As .it is impossible topredict'the nature of the defect and'the re sultant behavior of the wire," my invention provides a relaywhich'in case. of .a defect inthe" wire will unfailingly stop" the 'wire advancing" mechanism regardless of the'nature of the defect;

lnxcasean'enlargement' occurs in the wire' cross=section sothat" it cannot'pass through the pilot core-tube, the advancing wire will'detach' theipilotcore-tube from its'holder and this will engage the scanning fingers and'will swing the body portion of the relay into the stopping -posi'-- ti'onr. As'aresult of this, the contact roller will"- losethesupport-ofthe wire "and, together with the'contactarm', and the attached switch, will move into the stopping position,-stopping the adva-nce ofthewire:

Y 7 10 Pivotally. attached to the body portion 9-is-the-'- On the other hand, when a discontinuity occurs in the wire, due to a break of the running out of the wire supply, the contact roller will again lose the support of the wire and, will fall, together with the contact arm and the switch, into the stopping position and thereby stopping the advance of the wire.

It is to be understood that form of my invention, herewith shown and described, is to be taken as a i'preferred example" of "the'ssame, and that various-changes in -the- -shape, size -and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of. the.-subjoined claims. Particularly, springs lfl and' l4 may be substituted for by equivalnt weights, roller [3 by a sliding contact member, and the mercury switch I! by a switch of other known type.

Lelaimz- 1. In combination with an electrically controlledswire insulating-machine, having-a= coretube slidably engaging. the incoming wire; atdu plicate core-tube, detachably mounted so -as .to slidably engage the incoming wire .atea remote point from said machine; a pivotally mounted-- relay, located-between said-machine and said duplicate core-tube, and comprising a springe pressed-contact member in association withanelectric switch adaptedto stop said machine by said electrical control when said contact mem ber loses contact with thewire; scanning fingers, attached to said relay, and adaptedto swing out from the path of the wire and to-causesaid contact member to losecontact with-thewire when said-fingers are engaged by said :duplicate core tubedetached and carriedby said incoming wire 2.. In combination with a wire insulating-machine having an electricallycontrolled wire ad-- vancing means and a core-tube with an orifice ,slidably' engaging the--incoming, uninsulated wire V a pilot core-tube, :having identically dimensioned orifice, detachably mounted so asto. slidably engage theincoming wire at a distance from said -machine; a relay located adjacent to the incoming wire between -said-machine :and-saidpilot core-tube and comprising a pivotally mounted--body portion; a spring-pressedcontact mem-iber, attached'tosaid. body portion, andbeing normally supported b'y'said wire; an electric switch, associated with said contact member, and adapted to stop saidwire advancingmeans by said. electrical controlwhen said contact member loses the supportof the wire; scanning'fingers, attached-to said body portion, and adapted. to swing away -from thewireand .tocaus'e said contact member to lose the supportof the wire.

when said fingers are engagediby thepilot coretuee detached and carried'bysaidlwire.

References Cited "inthe file'of this patent UNITED STATES PATENTS Number Name Date 2,128,476 Runton AugZBO; 1938 2,248,315 Wachsman i .July 8,1941 2,430,893 Todd Nov.' 18; 1947 

